A gas turbine generally comprises a compressor, a combustor, and a turbine, wherein the compressor provides compressed air generated by a plurality of compressor blades to a combustion chamber of the combustor through a plurality of swirler inlet cups and a hot gas generated by the compressed air in the combustion chamber is provided to the turbine. Even though the plurality of swirler inlet cups are placed in the different positions of the combustor, the plurality of swirler inlet cups have the same length and the same bell mouth. As a result, when the compressed air flows through the plurality of swirler inlet cups, the air-flow is separated and air pockets are formed in the swirler inlet cups. That is, the air-flow is not uniform in the swirler inlet cups and thus flame-holding events occur in the combustion chamber.